Excelsior-knife



No. 624,5l4. Patented May 9, i899. D. T. H. MAcKINNON.

EXGELSIOR KNIFE.

(Application filed Apr. ,4, 1895.)

(N0 Model.)

7' a TI-qi NrrED STATES PATENT OFFICE.

DUNCAN T. H. MAOKINNON, OF MENASHA, \VISCONSIN.

,EXCELSI'OR-KNIFE.

SPECIFICATION forming part of Letters Patent No. 624,514, dated May 9, 1899.

Application filed April 4, 1898. Serial No. 676,487. (No model.) I

To all whom it may concern.-

Be it known that I, DUNCAN T. H. MACKIN- NON, a citizen of the United States, and a resident of Menasha, in the countyof Winnebago and State of Wisconsin, have invented a new and useful Improvement in Excelsior-Knives, of which the following is a specification, reference being had to the accompanying drawings.

My invention relates to a knife for use in cutting excelsior, it being fastened to the 1n achine and reciprocated over the block of wood to be cut; and it consists of formingaseries of parallel grooves having vertical walls lengthwise of the face of the knife; and its object is to cut the thin shaving of wood into narrow strips without the use of scoring-knives or knives for dividing the broad shaving into narrow strips and, furthermore, to leave the narrow strips separate and distinct from each other or so they will fall from the block in such a separated form as the user and general trade demand.

In the drawings, Figure 1 is a plan view of the knife. Fig. 2 is an edge view of the same. Fig. 3 is a sectional view taken on the line a a of Fig. 1. Fig. 4 is a plan of the cutting portion of the knife, showing a modification in the arrangement of the grooves; and Fig. 5 is a sectional view taken on the line b b of Fig. 4.;

Similar numerals indicate like parts in the several views.

1. 1 indicate the shank or securing part of the knife; 2 2, its cutting part; 3 3 and 4:, grooves in face of knife; 5 5, lands or spaces between the grooves; 6 6, the highest side walls of the grooves; 7 7, the lowest side walls; 8, a bevel upon the cutting end of knife; 9, a block of wood.

I am aware that eXcelsior-knives have been made having a series of grooves cut into their faces for the purpose of dispensing with the scoring-knives, as in the patent to H. C. Oloyd, dated April 8, 1893, No. 496,879, the grooves of which consist of one vertical wall and one inclined wall, the latter constituting thebottom of the groove, which extends from the lowest extremity of the vertical wall to thehighest point of the adjoining vertical wall, with the result of leaving the strips as they fall from the block in a twisted mass which is hard to separate and distribute evenly when less depth toward the part I until they run out before reaching said part; but it is preferable to have the cutting part enough thicker than the part 1 to allow for the depth of the grooves before reaching said thinner part, as it is here shown to be.

The knives are fitted for use by planing a series of parallel grooves lengthwise thereof, and the lands or the spaces between the grooves are of substantially the same width,

which width may be varied to suit the grade or fineness of excelsior which it is desired to make. Both sides of each groove are cut into the face of the knife at a right angle to said face, one being cut in but slightly and the other to nearly or quite double said depth and forming thereby perpendicular walls alongside of the adjoining lands, the bottom of the grooves being cut' upon a straight linefrom the bottom of one wall to the bottom of its companion wall. The outer end of the cutting part 2 is then beveled oil, as shown in the bevel 8, Fig. 2, so that the knife .being placed at an angle with the block, as shown insaid figure, the sharpened point'of the lands will first cut into the block and then the sharpened ends of the grooves, the side walls of the grooves separating the shaving cut by the former from the one out by the latter and leaving the surface of the block nearly smooth, the former out being only about the thickness of a piece of paper deeper into the wood than the latter, provided the angle of the knife with the block and the bevel 0f the end are adapted to each other. By making the knife in-this manner much time is saved by the workman both in the sharpening and setting of the knife over the time required when they are made plain and requiringa large number of scoring-knives. Other knives produce a large quantity of refuse, consist ng prlncipally of coarse dust and hue shavings, while these make comparatively none.

Figs. 1 and 3 show the lowest wall 7 of each groove alongside of alternate lands, while Figs. 4 and 5 show the lowest wall '7 of each groove alongside of the land upon its righthand side. Both the manner of making and of using the knives of the two forms and also the quality of their product are comparatively the same.

Having described my invention, what I claim, and desire to secure by Letters Patent, 1s

, An excelsior-knife having its cutting edge beveled on its under side, and having formed in the upper face of its body a plurality of longitudinal grooves,each of which is bounded by DUNCAN T. H. MAOKINNON.

Witnesses:

HARRY DE WOLF, S. J. PINKERTON. 

